<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    
</body>
</html>
<script>

    class Fu{
        constructor(name,age){
            this.name = name;
            this.age = age;
            
        }
        say(){
                console.log(this.name);
            }
    }

    class Zi extends Fu{
        constructor(name,age){
            super(name,age)
            this.say()
        }
    }
    new Zi('小张',20)
</script>